This invention relates to a cable holder which holds that portion of a flexible flat cable adjacent to a distal end thereof, thereby facilitating the connection of the flexible flat cable to a connector, and the invention also relates to a fixing method of fixing the flexible flat cable to the cable holder.
Signal-transferring cables, which enable the connection of a plurality of wires with high reliability, include a flexible printed circuit board (hereinafter referred to as xe2x80x9cFPCxe2x80x9d), having wires printed on a film, and a flexible flat cable (hereinafter referred to as xe2x80x9cFFCxe2x80x9d) having flat-type soft copper wires covered with a film. For connecting these cables to a connector, there has been used a method in which a distal end portion of the cable is grasped, and then is inserted directly into the connector. In the case of using an FPC, there has been proposed techniques (for instance, Japanese Utility Model Unexamined Publication No. 5-62980) in which a cable holder is used. More specifically, when attaching a panel having the FPC to a body having a connector, the cable holder holds that portion of the cable adjacent to a distal end thereof. This construction eliminates a troublesome operation in which the distal end portion of the cable is grasped, and then is inserted into the connector, and this also eliminates an incomplete insertion of the FPC and an incomplete locking of the connector.
However, when the above method is applied to an FFC, the following problem has been encountered. In the conventional technique, in order to prevent a cable from being disengaged from a cable holder, retaining pins are formed on the cable holder. Also, holes for respectively receiving the retaining pins are formed in that portion of the cable to be held by the cable holder. FIG. 8 shows a condition in which in order to apply a similar method to an FFC, holes 91 for respectively retaining the pins are formed on a distal end portion of the cable.
Since the FFC is a cable having flat-type soft copper wires covered with a film, the wires are disposed in parallel, having the same intervals. Therefore, when the holes 91 are formed, two (or more) wires 92 are cut or severed, and can not be used. Thus, there has been encountered a problem that the rate of utilization of the cable has been lowered.
The present invention has been made in order to overcome the above problem, and an object of the invention is to provide a cable holder which prevents a cable utilization rate from being lowered even if the cable holder holds an FFC.
Another object of the invention is to provide a cable holder which achieves the above object, and can be mounted on a plate member such as a chassis.
Further object of the invention is to provide a cable holder which achieves the above objects, and in which when the cable holder is mounted on the plate member, a cable body can be led out at that side of the plate member where a connector, to which a flexible-flat cable is to be connected, is disposed.
Still further object of the invention is to provide a cable fixing method which facilitates a fixing operation when fixing a flexible flat cable to a cable holder, using an adhesive.
To achieve the objects, according to a first aspect of the invention provides a cable holder for holding a flexible flat cable having a film portion, flat wires running in the film portion, a reinforcement portion where a reinforcement sheet is attached and notches formed respectively in opposite side edges of the reinforcement portion, to electrically connecting the flexible flat cable to a connector, the cable holder comprising: a holder body; a holder guide portion provided with the holder body, wherein an inner shape of the holder guide corresponds to an outer shape of the connector; and a cable holding portion having protuberances formed on the cable holding portion, for engaging respectively in the notches for holding the reinforcement portion of the flexible flat cable such that a distal end of the flexible flat cable projects into the holder guide portion.
According to a second aspect, there is provided a cable holder for holding a flexible flat cable having an end portion, and connecting the end portion of the flexible flat cable to a connector, the cable holder comprising: a holder body; a holder guide portion provided with the holder body, wherein an inner shape of the holder guide corresponds to an outer shape of the connector; a cable holding portion provided with the holder body for holding the end portion of the flexible flat cable; and a pouring hole is formed in a wall of the cable holding portion wherein the flexible flat cable is fixedly secured to the holder body by an adhesive poured into the cable holding portion through the pouring hole.
According to a third aspect, there is provided a cable holder according to the first or second aspect, further comprising: a holder holding portion for holding the holder body on a holder holding hole formed in a plate member.
According to a fourth aspect, there is provided a cable holder according to the third aspect, further comprising: a lead-out opening is disposed on that side of the plate member where the holder guide portion is disposed, for leading the flexible flat cable from the cable holding portion while the holder body is held on the plate member by the holder holding portion.
According to a fifth aspect, there is provided a fixing method of fixing a flexible flat cable to a cable holder in order to connect the flexible flat cable to a connector, comprising the steps of: (a) engaging a holder guide portion of the cable holder with a positioning adaptor having an outer shape corresponding to an inner surface of the holder guide portion having a shape corresponding to an outer shape of the connector, the positioning adaptor having a positioning slit of a predetermined depth formed at a position corresponding to an insertion slit in the connector; (b) inserting a distal end portion of the flexible flat cable into a lead-out opening, which leads the flexible flat cable out of a cable holding portion, until the distal end portion reaches a bottom of the positioning slit; and (c) pouring an adhesive through a pouring hole formed in the cable holding portion, with the distal end portion held in contact with the bottom of the positioning slit.